Data processing system





1. IN A SYSTEM COMPRISING A DATA STORAGE UNIT FOR STORING A PLURALITY OFDATA ITEMS AND A DATA PROCESSING UNIT CONNECTED TO COMMUNICATE WITH SAIDDATA STORAGE UNIT AND ADAPTED TO EXECUTE A PROGRAM OF DISTINCT COMMANDSIN SEQUENTIAL ORDER BY EXECUTING CORRESPONDING DISTINCT OPERATIONS ONSAID DATA ITEMS, WHEREIN SAID DATA PROCESSING UNIT IS TO BE DENIEDCOMMUNICATION WITH SAID DATA STORAGE UNIT FOR AN INTERVAL; MEANS TOPROVIDE A SIGNAL PRIOR TO SAID INTERVAL; MEANS RESPONSIVE TO SAID SIGNALFOR INTERRUPTING, FOR THE DURATION OF SAID INTERVAL, EXECUTION OFOPERATIONS WHICH ARE ADAPTED TO CONTINUE THROUGH SAID INTERVAL AND TOREQUIRE SAID DATA PROCESSING UNIT TO COMMUNICATE WITH SAID DATA STORAGEUNIT DURING SAID INTERVAL; AND MEANS RESPONSIVE TO SAID SIGNAL FORINTERRUPTING, FOR THE DURATION OF SAID INTERVAL, EXECUTION OF SAIDPROGRAM WHEN THE OPERATION BEING EXECUTED WHEN SAID SIGNAL OCCURSTERMINATES BEFORE SAID INTERVAL.